1 1 


C  I  RC 


ULAR    PiQ._7l    [RtV^ION    Qt     ClMCUlAB    NO     -JAL^ 


iTKIllllirc 


BUREAU    OP    ENTOMOLOGY, 


i  I       lltftyK  IJIIv     I'     J1! 

•  ■  II  r  lond 

l'.\    L.  ' ».   How  i 

Tin ti •  at  "t  Hies  which  are  commonly  found  in  hoi 

although  I'm  one  nl  |  iuld  !><•  called  tl  fly  proper.     This 

\e  tli>'    Vusca  tloniettiim   I     (fig.  M  ikiul   is  i    grayish  fly, 

with  it-  mouth  parts  spread  out  al  the  tip  foi  Bucking  up  liquid  sub- 
stances.  It  breeds  in  manure  and  dooryard  filth  and  is  found  in  nearly 
all  parts  of  the  world.     On  account  of  the  conforn  ts  mouth 


• 

the  Im'Um    fly  i  ■  ronger  in  the 

minds  of  mosl  people  than  that  this  insect  do(  onallybite.    This 

impression   is  due  to  th(  in  houses  of  another  fly 

N  .  which  table  fly 

which,  while  closely  resembling  the  hous  .  in  facl 

to  d<  i  eive  anyone  but  an  entomo  >m  it  in  the  important 

particular  that  it-  mouth  parts  are  formed  for  piercing  the  .-kin.     It  is 
nd  in  point  of  abund  -•   fly  in  most  portions 

of  the  Northeastern  Stat 

A  third f  monly  called  th<  Pollenia  rndixl 

is  a  tant  '•!  houses,  particularly  in  the  spring  and  fall. 

This  fly  i-  somewhat   larger  than  the  house  fly,  with  a  dark-col 
smooth  abdomen  and  a  sprinkling  of  yellowish  hairs.    It  i  —        -     ictive 
as  tl)-1  house  fly  and.  particularly  in  the  fall,    - 


times  it  may  be  picked  up  readily  and  is  very  subject  to  the  attacks  of 
a  fungous  disease  which  causes  it  to  die  upon  window  panes,  surrounded 
by  a  whitish  efflorescence.  Occasionally  this  fly  occurs  in  houses  in 
such  numbers  as  to  cause  great  annoyance,  but  such  occurrences  are 
comparatively  rare. 

A  fourth  species  is  another  stable  fly,  known  a-  Muscina  stabulans 
Fall.  C  f i t-T -  3),  a  form  which  almost  exactly  resembles  the  house  fly  in 
general  appearance,  and  which  does  not  bite  as  does  the  biting  stable 
fly.     It  breeds  in  decaying  vegetable  matter  and  in  excrement. 

Several  species  of  metallic  greenish  or  bluish  Hies  are  also  occasion- 
ally found  in  houses,  the  most  abundant  of  which  is  the  so-called  blue- 
bottle fly  (Calliphora  erythrocephala  Meig.).  This  insect  is  also  called 
the  blow-fly  or  meat-fly  and  breeds  in  decaying  animal  material.  A 
smaller  species,  which  may  he  called  the  small  blue-bottle  fly,  is  Phorniia 


]'n.  2.— Stomoxyt  calc  t kius    Adult,  larva,  puparium  and  detail: 

illustration 


A  l  i  olarg<  •!  author's 


terramova  Desv.  (fig.  4);  and  a  third,  which  is  green  in  color  and  about 
the  size  of  the  large  blue-bottle,  is  Lucilia  ccesar  1..  (fig.  5). 

There  is  still  another  species,  smaller  than  any  of  those  so  far  men- 
tioned, which  is  known  to  entomologists  as  Homalomyia  canicularis  L.. 
sometimes  called  the  small  house  fly.  A  related  species,  //.  brevis 
Rond.,  is  shown  in  figure  6.  //.  canicularis  is  distinguished  from  the 
ordinary  house  fly  by  its  paler  and  more  pointed  body  and  conical 
shape.  The  male,  which  is  much  commoner  than  the  female,  has  large 
pale  patches  at  the  base  of  the  abdomen,  which  are  translucent  when 
l  he  fly  is  seen  on  a  window  pane.  It  is  this  species  that  is  largely 
responsible  tor  the  prevalent  idea  that  Hies  grow  after  gaining  wings. 
.Most  people  think  that  these  little  Homalomyias  are  the  young  of  the 
larger   Hies,  which,  of  course,  is  distinctly  not  the  case. 

Still  another  fly,  and  this  one  is  still  smaller,  is  a  jet-black  species 
known  as  the  window  By  ( Scenopinus  fenestratis  L.),  which  in  fact  has 


1  in' l.i ni   of  I  I  ■    '        I-   111   i In ■  .ln-i  umlei 

<-  irpets    hi  I  ImoHl  thread-like  erenture. 

In  the  autumn,  when  fruil  appi  irs  on  the  sid<  b  ■  ird   in  u  mens 

-in. ill  iruit  i!       Ih    tophi la  n  in  pel  op  hi In   Li'i'i'  their 

appi  I    bj    the    odoi    ol 

overripe  fruil 

\  small   -  •  ader  tl>  i-  not  infrequently 
Been  in  hi  pe<  ialhi  upon  \\  indow 

panes.     This   i-   >  Moi 

show ii  enlarged  in  figun   - 

All    of    tin- 
greatly  dwarfed  in  numhera  bj  thi 
mon  house  il\ .    I n  1901 '  the  \\i iter  made 
colled ions  ..I  the  Hies  in  dining  rooms 
in  different  parte  ol  the  country  .  and  out 
total  of  23,087  Hies    22,808    were 
\£um  n  (lo- 
rn <  <f  t  i  ( 
thai  ie  9«  - 

per  i  enl    ol  the  whole   numb  pi  ured. 

The  remainder,  consisting  ol  1.2  pei  cenl 
n|  the  whole,  comprised  various  Bpecies, 
including  those  mentioned  abo 

LIFE  ill-  I '  >l,"i    I  IF    ri'  H(  'i  -I.  II. V. 

1/ ust  it  donii  immonly  laj  - 

upon  horse  manure.  This  Bubstance  seems 
to  be  it-  favorite  larval  food.     Ii  will  ovi- 

DOSil      ''II 

•>\  ma- 
nure, bul  we  have  nol  been  able  to  rear 
it  iii  this  Bubstance.  It  will  ah 
in  human  excrement,  and  from  this 
habit  it  becomes  very  dangerous  to  the  ^v 
health  of  human  beings,  carrying,  as 
it  does,  tin  germs  ol  in  test  inal  dis- 
-utli  ;i>  typhoid  fever  and  cholera 
from  excreta  to  food  supplies.  It  will 
also  lay  ii  upon  othei  decaying 

vegetable  and  ajiimaJ  material,  but  "I 
the  flies  that  infest  dwelling  housi  -. 
both  in  cities  and  on  farms,  a  vosl 
proportion  comes  from  horse  manure. 

At  Salem,  Mass.,  Packard  states  thai   he  bred  a  generation  in  I 
teen  days  in  horse  manure.     The  duration  "t  the  ■  •   was  twenty- 


lllusl 


lour  hours,  the  larval  state  from  five  t<>  seven  days,  and  the  pupal  state 
from  five  to  seven  days.  At  Washington  the  writer  has  found  in  mid- 
summer that  each  female  lays  about  120  eggs,  which  hatch  in  eight 
hours,  the  larva  period  lasting  live  days  and  the  pupa  live  days,  making 
the  total  time  for  the  development  of  the  generation  ten  days.  This  was 
at  the  end  of  June.  The  periods  of  development  vary  with  the  climate 
and  with  the  season,  and  the  insect  hibernates  in  the  puparium  condi- 
tion in  manure  or  at  the  surface  of  the  mound  under  a  manure  heap. 
It  also  hibernates  in  houses  as  adult,  hiding  in  crevio  3. 

The  Washington  observations  indicate  that  the  larva-  molt  twice, 
and  that  there  are  thus  three  distinct  larval  stages. 

The  periods  of  development  were  found  to  be  about  as  follows:  Egg 
from  deposition   to   hatching,  one-third   of  a   day;   hatching  of  larva  to 


Fig  ti.—Homalomyia  brevis:    Female  at  left;    male  next,  with  enlarged  antenna;    larva  ;it  right. 
All  enlarged  (author's  illustration 

first  molt,  one  day  :  first  to  second  molt,  one  day  :  second  molt  to  pupa- 
tion, three  days:  pupation  to  issuing  of  the  adult,  live  days:  total  life 
round,  approximately  ten  days.  There  is  thus  abundance  of  time  for 
the  development  of  twelve  or  thirteen  generations  in  the  climate  of 
Washington  every  summer. 

The  number,  of  eggs  laid  by  an  individual  fly  is  undoubtedly  large, 
averaging  about  120,  and  the  enormous  numbers  in  which  the  insects 
occur  is  thus  plainly  accounted  for.  especially  when  we  consider  the 
abundance  and  universal  occurrence  of  appropriate  larval  food.  In 
order  to  ascertain  the  numbers  in  which  house-fly  larva?  occur  in  horse- 
manure  piles,  a  quarter  of  a  pound  of  rather  well-infested  horse  manure 
was  taken  on  August  9,  and  in  it  were  counted  160  larva-  and  111! 
puparia.  This  would  make  about  1,200  house  flies  to  the  pound  of 
manure.  This,  however,  can  not  he  taken  as  an  average,  since  no  larva- 
are  found  in  perhaps  the  greater  part  of  ordinary  horse-manure  piles. 
Neither,  however,  does  it  show  the  limit  of  what  can  be  found,  since 
about  200  puparia  were  found  in  less  than  1  cubic  inch  of  manure  taken 


from  a  spot  2  inches  below  th<    Burface  of  the  pile  where  the  larva   had 
congregated  in  immense  numbers.     The  different  »l  the  ii 

are  well  illustrated  in  figure  I  and  need  l<  b<  ription. 

i.imi  mi  -    \\i<   ri;i:\  i:\ii\i  s. 

A  careful  screening  ol  windows  and  doors  during  the  summer  months, 
with  the  supplemental*}  use  of  sticky  fly  papers  is  i  preventive  m< 
against  house  ili<~  known  t<>  everyone,  and  there  Beems  to  be  little 
hope  in  the  near  future  of  much  reliel  by  doing  away  w  itli  the  l ■!■  ■«•< I i 1 1 lt 
places.  A  Bingle  Btable  in  which  a  horse  is  kept  will  Bupply  house  Mi<s 
foi  an  extended  neighborhood.  People  living  in  agricultural  commu- 
nities will  probably  never  !"•  rid  ■>!  the  p<--t.  but  in  <  i ( i<~ .  with  better 
methods  "t  disposal  "i  garbage  and  with  the  lessening  "I  the  number 
ol   horses  and  horse  Btables  consequent   upon  electrii  railways, 

bicycles,    and    automobiles,    the    time    may    come,    and    before    very 


• 


/ 


> 


I'iuni  fr.  mi   i 

long,  when  window  screens  may  be  discarded.  The  prompt  gathering 
of  horse  manure,  which  may  be  variously  treated  or  kept  in  a  specially 
prepared  r<  ceptacle,  would  greatly  abate  the  fly  nuisance,  and  city  ordi- 
nances compelling  horse  owners  to  follow  some  such  course  are  desir- 
able. Absolute  cleanliness,  even  under  existing  circums  will 
always  result  in  a  diminution  <>f  the  numbers  ol  the  house  ily.  and,  in 
fact,  most  household  insects  are  less  attrai  ted  to  the  premises  of  what 
is  known  as  the  old-fashioned  housekeeper  than  to  those  of  the  other 
kind. 

During  tht>  summer  of  1897  a  series  of  experiments  was  carried  out 
with  the  intention  of  Bhowing  whether  it  would  ;  ble  to  tn 

manure  pile  in  such  a  way  a-  to  -top  the  breeding  ol  tli<-~.  The  writer's 
experience  with  the  use  ol  air-slaked  lime  on  cow  manure  to  prevent 
tlic  breeding  ■>'  the  horn  fly  Buggested  experimentation  with  <lit'i' 


fi 


lime  compounds.  It  was  found  to  be  perfectly  impracticable  to  use  air- 
slaked  lime,  land  plaster,  or  gas  lime  with  good  results.  Few  or  no 
larva'  were  killed  by  a  thorough  mixing  of  the  manure  with  any  of 
these  three  substances.  Chlorid  of  lime,  however,  was  found  to  be  an 
excellent  maggot  killer.  Where  1  pound  of  chlorid  of  lime  was  mixed 
with  8  quarts  of  horse  manure,  90  per  cent  of  the  maggots  were  killed 
in  less  than  twenty-four  hours.  At  the  rate  of  a  quarter  of  a  pound  of 
chlorid  of  lime  to  8  quarts  of  manure,  however,  the  substance  was 
found  not  to  be  sufficiently  strong.  Chlorid  of  lime,  though  cheap  in 
Europe,  costs  at  least  •">■!.  cents  a  pound  in  large  quantities  in  this 
country,  so  that  the  frequent  treatment  of  a  large  manure  pile  with 
this  substance  would  be  out  of  the  question  in  actual  practice. 

Experiments  were  therefore  carried  on  with  kerosene.     It  was  found 


Pig   B.— Sepsis  violacea:  Adult  with  enlarged  antenna  at  right;  puparium 
;it  left.    All  enlarged  (author's  illustrat 

that  8  (piarts  of  fresh  horse  manure  sprayed  with  1  pint  of  kerosene, 
which  was  afterwards  washed  down  with  1  quart  of  water,  was  thor- 
oughly rid  of  living  maggots.  Every  individual  was  killed  by  the 
treatment.  This  experiment  and  others  of  a  similar  nature  on  a  small 
scale  were  so  satisfactory  that  it  was  considered  at  the  close  of  the 
season  that  a  practical  conclusion  had  been  reached,  and  that  it  was 
perfectly  possible  to  treat  any  manure  pile  economically  and  in  such  a 
way  as  to  prevent  the  breeding  of  Hies. 

Practical  work  in  the  summer  of  1898,  however,  demonstrated  that 
this  was  simply  another  case  where  an  experiment  on  a  small  scale 
has  failed  to  develop  points  which  in  practical  work  would  vitiate  the 
results. 

The  stable  of  the  U.  S.  Department  of  Agriculture,  in  which  about 
twelve  horses  are  kept,  is  situated  about  100  yards  behind  the  main 
building  of  the  Department  and  about  !><>  yards  from  the  building  in 


which  the  Bun  tu  ol   Entomol  ituated      This   stable  has  always 

been  ver^  carefully  kept.     The  manure  was  thorough!]  3wep1   up  i 
morn  ied  outside  ol  the  Btable,  and  deposited  in  a  pile  behind 

the  building.     This  pile,  aftei   accumulating  for  .1  week  or  ten  daj 
sometimes   two   weeks,  was  carried  of!   by  the  gardeners  find   -1 
upon  distanl  portions  of  the  grounds.     At  all  times  in  the  Bummer  this 
manure  pile  swarmed  with  the  m  >1  the  h<  use  Hy.     It  is  Bafe  to 

>,i\  thai  "ii  an  average  many  thousands  oi  perfecl  Hies  issued  from  it 
ever}   day,  and  thai  ;it  leasl  a  large  -  the  Hies  which  constantly 

bothered  the  employees  in  the  two  buildings  mentioned  came  from  this 
Boun 

On  the  basis  ol  the  experiment*  ol  lv>7.  an  attempl  \\:i-  made, 
beginning  early  in  April,  1898,  to  prevenl  the  breeding  of  bouse  Hies 
about  the  Departmenl  by  the  treatmenl  of  this  manure  pile  with  kero- 
Bene.  The  attempl  was  begun  early  in  April  and  was  carried  <>n  for 
some  weeks.  While  undoubtedly  hundreds  of  thousands  of  flies  were 
destroyed  in  the  course  of  this  work,  it  was  found  by  the  end  of  May 
that  it  was  far  from  perfect,  since  if  used  at  an  economical  rate  the  kero- 
Bene  could  nol  be  made  to  penetrate  throughoul  the  whole  pile  "I 
manure,  even  when  copiously  washed  down  with  water.  A  considerable 
proportion  ol  house-fly  larva;  escaped  injury  from  this  treatment,  which 
at  the  same  time  was  found,  even  at  an  economical  cost,  to  be  laborious, 
and  such  a  measure,  in  int.  as  almosl  no  one  could  he  induced  t<>  prac- 
tically adopl . 

There  remained,  however,  another  measure  which  had  been  si 
by  the  writer  in  an  article  on  the  bouse  fly  published  in  1895,  namely, 
the  preparation  of  an  especial  receptacle  tor  the  manure,  ami  this  was 
very  readily  accomplished.  A  closel  6  bj  8  feel  had  been  buill  in  the 
corner  of  the  Btable  nearesl  the  manure  pile.  It  had  a  door  opening  into 
the  stable  proper,  and  also  a  window.  A  door  was  luiilt  in  the  outside 
wall  ot  tl  t,  and  the  Btablemen  were  directed  to  place  no  1 

manure  outside  the  building;  in  other  words,  to  abolish  the  outside 
manure  pile,  and  in  the  future  to  throw  all  of  the  manure  collected  each 
morning  into  this  closet,  the  window  of  which  in  the  meantime  had 
hccii  furnished  with  a  wi  n.     The  preparations  ompleted 

by  the  middle  of  June,  and  a  barrel  of  chlorid  of  lime  was  put  in  the 
corner  .■!  the  closet.  Since  that  time  every  morning  the  manure  of  the 
Btable  i-  thrown  into  the  closet,  and  a  small  shovelful  of  chlorid  of 
lime  i-  -caitercd  over  it.  At  the  expiration  of  ten  day-  or  two  weeks 
the  gardeners  open  tin-  outside  door,  -hovel  the  manure  into  a  cart,  and 
carry  it  off  to  he  thrown  upon  the  grounds. 

Judging  from  actual  examination  of  the  manure  pile,  the  measure  is 
eminently  successful.  Very  few  flies  arc  breeding  in  the  producl  of  the 
stable  which  formerly  gave  birth  to  many  thousands  daily.  Alter  this 
measure  had  been  carried  on  for  two  weeks,  employees  ol  the  Depart- 


8 

merit  who  had  tio  knowledge  of  the  work  that  was  going  <>n  were  asked 
whether  they  had  nut  iced  any  diminution  in  the  number  of  flies  in  their 
offices.  Persons  in  all  of  the  offices  on  the  firsl  floor  of  the  two  build- 
ings were  asked  this  question.  In  every  office  except  one  the  answer 
was  thai  a  marked  decrease  had  been  noticed,  so  that  the  work  must  he 
considered  to  have  been  successful. 

The  account  of  this  remedial  work  has  been  given  with  some  detail. 
since  it  shows  so  plainly  that  care  and  cleanliness  combined  with  such 
an  arrangement  as  that  described  will  in  an  individual  stable  measur- 
ably affeel  the  fly  nuisance  in  neighboring  buildings. 

With  the  combined  efforts  of  the  persons  owning  stables  in  a  given 
community,  much  more  effective  results  can  undoubtedly  he  gained. 

In  the  consideration  of  these  measures  we  have  not  touched  upon  the 
remedies  for  house  flies  breeding  in  human  excrement.  On  account  of 
the  danger  of  the  carriage  of  typhoid  fever,  the  dropping  of  human 
excrement  in  the  open  in  cities  or  towns,  either  on  vacant  lots  or  in 
dark  alleyways,  should  hi'  made  a  misdemeanor,  and  the  same  care 
should  he  taken  by  the  sanitary  authorities  to  remove  or  cover  up  such 
depositions  as  is  taken  in  the  removal  of  the  bodies  of  dead  animals. 
The  box  privy  is  always  a  nuisance  from  many  points  of  view  and  is 
undoubtedly  dangerous  as  a  breeder  of  flies  which  may  carry  the  germs 
of  intestinal  disease.  No  box  privies  should  he  permitted  to  exist  unless 
they  are  conducted  on  the  earth-closet  principle.  With  a  proper  vault 
or  other  receptacle,  closed  except  from  above,  and  a  free  use  of  fine 
earth,  the  breeding  of  house  flies  can  he  prevented.  Covering  the  sur- 
face with  lime,  however,  is  more  certain  than  the  use  of  earth.  The 
writer  has  seen,  in  a  large  camp  of  volunteer  soldiery,  unprotected  sinks 
in  which  the  house  fly  was  breeding  by  the  thousands.  lie  has  also 
seen  permanent  camps  in  which  the  sinks  were  so  constructed  and  so 
treated  with  lime  that  no  house  Hies  whatever  were  present. 

A  Parisian  journal,  the  Matin,  during  the  winter  of  1905-6,  estab- 
lished a  prize  of  10,000  francs  for  the  best  essay  on  the  destruction 
of  the  house  fly.  The  jury  of  competent  scientific  men  awarded  the 
prize  to  the  author  of  a  memoir  in  which  it  was  proposed  to  use  residuum 
oil  in  the  destruction  of  the  eggs  and  larva' of  the  fly.  This  oil  is  to  he 
used  in  privies  and  cesspools.  Two  liters  per  superficial  meter  of  the 
pit  is  mixed  with  water,  stirred  with  a  stick  of  wood,  and  then  thrown 
into  the  receptacle.  It  is  said  to  form  a  covering  of  oil  which  kills  all 
the  larva  .  prevents  the  entrance  of  flics  into  the  pit  and.  at  the  same 
time,  the  hatching  of  eggs.  It  makes  a  protective  covering  for  the 
excrement,  and  this  is  said  to  hasten  the  development  of  anaerobic  bac- 
teria as  in  a  true  septic  pit.  leading  in  this  way  to  the  rapid  liquefaction 
i  if  Mil  id  matters  and  rendering  them  much  more  unfit  for  the  development 
of  other  bacteria.  For  manure  it  is  recommended  to  mix  this  residuum 
oil    with    earth,  with    lime,  anil    with    phosphates,   and    to   spread    it    at 


differenl  times,  in  th(      pring   bj    pref<  upon  the  manun  ol  I 

ami  - 1 . 1 1 < I « -  and  ~.i  on. 

Practical  experimentation  with  this  proposed  remedy  will  be  undei 
taken  1 1 ng  spring  in  Pram  i 


\  \  i  i  K  \i.   i  \i;\iii:>. 


The    house    fly    has  a   number   of  natural  enemies.     The    common 
house  centipede  (fig.  9)  destroys  il  in  considerable  numbers,  tl 
-iii.-i  11   reddish   mite   which   frequently   covers   its   body   and   gradually 
destroys  it.il  is  subjeel  to  the  attacks  of  hymenopterous  parasite?  in  its 


\   lu't     ■ 

larval  condition,  and   it   is  destroyed  by  inn  la  ion-  I » . 
time. 

rhe  mosl  effective  enemy,  however,  is  a  fungous  disease  known  as 
Empusina  musae,  which  carries  off  flies  in  large  numbers,  particularly 
toward  the  close  ol  the   season.      The  epidemic  tnber, 

and  although  many  thousands  are  killed  by  it,  the  remarkable  rapidity 
of  development  in  the  early  summer  months  soon  more  than  replaces 
the  thousands  thus  destroyed. 

Approved : 

James  Wilson, 

n.  en  tary  •  iltui  i 

VV  ashing  roN,  D   ('..  Man  h  27    190 


UNIVERSITY  OF  FLORIDA 


3  1262  09216  6205 


